title: Ultrashort-pulse lasers treating the crystalline lens: will they cause vision-threatening cataract? (An American Ophthalmological Society thesis).
abstract: OBJECTIVE
  To demonstrate that ultrashort-pulse laser treatment in the crystalline lens does not form a focal, progressive, or vision-threatening cataract.
  
  
  METHODS
  An Nd:vanadate picosecond laser (10 ps) with prototype delivery system was used. Primates: 11 rhesus monkey eyes were prospectively treated at the University of Wisconsin (energy 25-45 μJ/pulse and 2.0-11.3M pulses per lens). Analysis of lens clarity and fundus imaging was assessed postoperatively for up to 4½ years (5 eyes). Humans: 80 presbyopic patients were prospectively treated in one eye at the Asian Eye Institute in the Philippines (energy 10 μJ/pulse and 0.45-1.45M pulses per lens). Analysis of lens clarity, best-corrected visual acuity, and subjective symptoms was performed at 1 month, prior to elective lens extraction.
  
  
  RESULTS
  Bubbles were immediately seen, with resolution within the first 24 to 48 hours. Afterwards, the laser pattern could be seen with faint, noncoalescing, pinpoint micro-opacities in both primate and human eyes. In primates, long-term follow-up at 4½ years showed no focal or progressive cataract, except in 2 eyes with preexisting cataract. In humans, <25% of patients with central sparing (0.75 and 1.0 mm radius) lost 2 or more lines of best spectacle-corrected visual acuity at 1 month, and >70% reported acceptable or better distance vision and no or mild symptoms. Meanwhile, >70% without sparing (0 and 0.5 mm radius) lost 2 or more lines, and most reported poor or severe vision and symptoms.
  
  
  CONCLUSIONS
  Focal, progressive, and vision-threatening cataracts can be avoided by lowering the laser energy, avoiding prior cataract, and sparing the center of the lens.
authors.affiliation: Cole Eye Institute & Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Ronald R
authors.initials: RR
authors.lastname: Krueger
authors.forename: Harvey
authors.initials: H
authors.lastname: Uy
authors.forename: Jared
authors.initials: J
authors.lastname: McDonald
authors.forename: Keith
authors.initials: K
authors.lastname: Edwards
mesh_terms: D000328:Adult; D000818:Animals; D002386:Cataract / Q000209:etiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D053685:Laser Therapy / Q000009:adverse effects / Q000379:methods; D007908:Lens, Crystalline / Q000528:radiation effects*; D008253:Macaca mulatta; D008297:Male; D008875:Middle Aged; D023421:Models, Animal; D011305:Presbyopia / Q000628:therapy*; D011446:Prospective Studies; D014638:Vanadates / Q000627:therapeutic use; D014792:Visual Acuity
chemical_list: D014638:Vanadates